I. Field of the Invention
The present invention relates generally to speed and position controllers and, more particularly, to such a device for controlling the speed of a controlled member along an axis of movement.
II. Description of the Prior Art
There are a plurality of previously known controllers, many of which control the position of a member along an axis of movement. These prior devices, however, typically cannot infinitely variably control the position of the controlled member along its travel. Rather, these prior devices can only shift the member to a finite and predetermined number of axial positions.
Furthermore, these previously known devices can control the position, but not the speed, of the member. For many applications, such as valve actuation, it is desirable to control the speed of the member. Lastly, these previously known devices are overly complex in design and, therefore, costly to manufacture. Moreover, due to their complexity and multiplicity of components, these previously known devices are prone to failure.